Electrochemical and physicochemical properties of titanium Oxy-nitride electrocatalyst prepared by sol-gel methods for the oxygen reduction reaction purposes

摘要

In the present article, titanium oxy-nitride (TiON), as a potential electrocatalyst for the oxygen reduction reaction (ORR), is fabricated by four different sol-gel methods. Physicochemical properties (structure, chemical composition, BET surface area, surface morphology, chemical stability, and electrochemical stability) are determined. The ORR in acid medium on these TiON electrocatalysts is evaluated and compared to the ORR on commercial Pt/C. This evaluation is based on the onset potential, charge density, Tafel slope, exchange current density, and mass activity. Chemical and electrochemical stability of TiON electrocatalysts are compared to those of platinum electrocatalyst. It is shown that the preparation method affects the electrocatalytic activity and stability. The stability of the TiON electrocatalysts is correlated to their chemical composition and BET surface area. In addition, the effect of the heat treatment condition on the chemical composition, surface area, and performance of the electrocatalysts are investigated. The best TiON electrocatalyst with a high content of nitrogen exhibited the onset potential of 0.75 V vs. NHE, which is quite promising for a non-noble electrocatalyst for the ORR in acid medium.